As the proportion of the American population that is elderly increases, there is a growing need for physician- scientists trained in health policy, economics, and social and behavioral sciences to address the numerous issues around the health care that the elderly population receives. Harvard University, home to a long established, nationally recognized MD-PhD program as well as world-renowned graduate programs in Health Policy, Economics, and Social and Behavioral Sciences, is exceptionally well poised to train physician-scientists in these areas. This training grant requests funding for a five-year period to support 2 pre-doctoral students for year 1, and 4 students for years 2-5. The typical training timeline would follow the `2-4-2' model: 2 years of medical school; 4 years of graduate school culminating in a PhD with at least one project focused on issues relevant to aging populations; and, then, 2 final years of medical school inclusive of a geriatric clinical elective. Other aging components include graduate level coursework in aging, monthly tutorials that will focus on age related topics, and shadowing a physician-scientist gerontologist. The Harvard/MIT MD-PhD Program at Harvard Medical School has an overall mission to train the next generation of leading physician-scientists across a variety of clinical disciplines and research areas from basic sciences to bioengineering to the social sciences. The program, comprised of over 175 students in various stages of training, integrates the medical and graduate training of a pool of extraordinarily talented students. The social science students, approximately 10% of the MD-PhD student body, create a close-knit community lead by a dedicated committee of faculty, who are focused on their unique training needs. Dr. Loren Walensky, the MD-PhD Program Faculty Director, has teamed up with Dr. Joseph Newhouse, chair of the Harvard PhD Program in Health Policy, who has been a longstanding member of this social science committee, to create this unique training opportunity. Graduate study will be offered in the following programs: Concentrations in Economics, Management, and Evaluative Science and Statistics in the Harvard PhD Program in Health Policy, which trains students for research and teaching careers in health policy through an interdisciplinary and interfaculty approach; Harvard PhD Program in Economics in the Department of Economics, which prepares students for productive and stimulating careers as economists in academia or for responsible positions in government, research organizations, or business enterprises; and, the SD in Social and Behavioral Sciences offered through Harvard School of Public Health, which trains its students to be scholars whose research will illuminate basic social determinants of health and who will identify and test innovative social policy and service interventions. The 19 faculty participating in this training program all possess a strong interest in and experience with mentoring physician-scientist trainees and most have expertise in issues related to aging populations.